CN1096518C - Driving device for oscillating shuttle of sewing machine - Google Patents

Abstract

A driving apparatus for an oscillating catcher of a sewing machine includes a toothed pinion being eccentrically mounted on a driving shaft for the catcher for the sewing machine. A transmission device, having teeth, is guided in a back-and-forth movement by an oscillating crank drive, with the teeth of the transmission device engaging the tooth pinion on the driving shaft. By arranging the toothed driving gear eccentrically on the driving shaft of the catcher, it is possible to substantially increase the speed of the point of the catcher when it seizes the loop of the upper thread offered by the needle.

Description

The transmission device of oscillating shuttle of sewing machine

Theme of the present invention is according to the claim 1 a kind of shuttle transmission device that is used for Sewing machines as described in the preamble.

The various embodiment that the shuttle transmission device is arranged from prior art as can be known.Its task is that shuttle is in the rotatablely moving of vibration, so that catch the upper thread coil with the shuttle tip, and to the bobbin case channeling conduct.Shuttle adopts a crank to drive under most situation, and crank is driven by a driving element rotation or swing, and drives a gear that is positioned on the shuttle power transmission shaft by a tooth bar.

In Swiss Patent document 241880, tooth bar carrying out with gear or tangential direction, and is fixed on by one that connecting rod on the crank drives on longitudinal guide.In british patent document 1,035, in 881, the tooth of tooth bar is to be set directly on the prolongation of connecting rod, and the latter makes it to carry out oscillating motion by a swing pull bar.These two kinds of transmission devices can be used for the shuttle of horizontal hunting, also can be used for the shuttle of vertical oscillation.

Foregoing two kinds of transmission devices have a shortcoming, promptly in the moment of coming receiving coil by the shuttle tip, the rotating speed that shuttle can reach is lower, but the rotating speed of shuttle can not change arbitrarily with known transmission device, because the actuation movement of doubly-linked purl mark sewing machine needle bar and shuttle must be synchronous operation.As long as sewing needle moves to middle zero-bit just, just can and not form Zig-zag, and the position of the motion of shuttle and sewing needle is in full accord to the side skew.The upper thread coil can be caught reliably and be guided equably.When making Zig-zag, phase place between pinprick and the shuttle tip has just changed, in the moment of coming receiving coil by shuttle, it and the instantaneous lateral location of sewing needle, just relevant to the position of side skew from middle position, when the shuttle tip was moved through sewing needle for the upper thread coil that is provided by sewing needle is provided, sewing needle is operation upwards.This side skew of sewing needle when Zig-zag must change the distance between pinprick and the shuttle tip.If this distance less than or greater than nominal distance, just bouncing pilotage can take place, because the shape and size of coil similarly change along with skew, and under worst situation, coil can't be caught in the shuttle tip.The maximum tooth width that may the reach skew of sewing needle just will be subjected to the influence of the phase deviation degree between pinprick and the shuttle and the upper limit is restricted.The acting on of this phase deviation discussed to some extent among the 3rd of " Sewing machines expert " book nineteen fifty-seven version that RentersShi writes and illustrated, therefore relevant when Zig-zag the further specifying here of relation of receiving coil just omitted.In a word clearly, by very little or, when existing receiving coil to close the deviation of fastening hardly, just can reach bigger tooth width in the ideal case as when making one vertical masonry joint.

Above-mentioned performance has illustrated that the speed of the relative motion between sewing needle and the shuttle has intense influence to the reliability of needle tracking and the maximum needle tracking width of the Zig-zag that may reach.Be not only moving of shank and pin, and be that the swing of shuttle will be depended on the kinetic characteristic (acceleration) that crank drives and produce uneven motion.For for the purpose of accept in the yarn coil zone to improve this movement relation by the shuttle tip or eliminate phase deviation between pinprick and shuttle tip, or the motion of the sewing needle that must slow down, or movement velocity that must the raising shuttle.

Therefore task of the present invention is to improve so foregoing this transmission device, enables to obtain a bigger needle tracking reliability and/or can reach bigger needle tracking width when Zig-zag.

This task is that the shuttle transmission device by the feature with claim 1 solves.

This is to achieve success in the speed of extracting during by upper thread coil that sewing needle provided by obviously improve the shuttle tip at the eccentric driven wheel that is provided with on the shuttle power transmission shaft.Gear is selected like this with respect to the angle position of the maximum eccentricity at shuttle tip, and promptly the shuttle tip is moved through sewing needle with the speed of maximum in grasping coil scope or time point.The eccentric pinion that is provided with can be made originally with lower one-tenth on the shuttle power transmission shaft.In order on gear, to guide tooth bar, a directed disc coaxial with eccentric gear can be set, it prevents that near thereon guide tooth bar from lifting from gear by one.In another kind of structure of the present invention, the tooth bar that preferably is arranged on connecting rod one end keeps being meshed with the tooth of tooth bar by spring force.

In another favourable structure of the present invention, be arranged in by tooth and can make the rate curve further optimization of shuttle tip when grasping coil on the curve tooth bar.Use an odontoid belt as transmission mechanism for noise problem, prove favourable.

The present invention is described in detail according to illustrated embodiment below.Wherein:

The side view of Fig. 1-free arm Sewing machines has the free arm of representing with longitudinal profile (rearmost position of tooth bar),

The perspective view of Fig. 2-free arm (shell is removed the back), tooth bar is positioned at the front extreme position,

The perspective view of Fig. 3-another kind of shuttle transmission device has a crank of opening and have the guider of tooth bar on an eccentric disk that is provided with;

Fig. 4-in the fashionable diagrammatic side view of thorn with shuttle of three pin positions,

The side view of the another kind of structure of Fig. 5-free arm Sewing machines has the free arm of representing with longitudinal profile.

The diagrammatic side view of expression one Sewing machines 1 wherein can be seen a casing 3 in Fig. 1, and the presser feet do not represented and the support of shank are housed free arm 5 below and on head 7 among the figure.For the purpose of more very clear, only express sewing needle 9 and do not express shank, so that can see its general position clearly.In the free arm 5 of side direction section, can see a crank gear 11 and hinged connecting rod 13 and tooth bar 15 on its front end on it in the left side, gear or pinion 17 that tooth bar 15 is same to be arranged on the power transmission shaft 19 of shuttle 21 prejudicially are meshed.Can see needle plate 23 on shuttle 21, sewing needle 9 can pass the pinprick 25 from needle plate.Crank gear 11 makes it rotation by a motor of not representing.Crank gear is what to be designed to the transmission synchronous operation of the shank of not expression and sewing needle 9 fixed thereon.Connecting rod 13 and the tooth bar of being adorned thereon 15 are in the position of back in Fig. 1, and sewing needle 9 is not meshed (sewing piece is not represented) with sewing piece as yet.Sewing needle 9 has passed pinprick 25 and has entered needle plate 23 in Fig. 2, and tooth bar 15 has reached the limit and the folded back position of its front end.On the front end extreme position, having from the tooth of minimum those teeth of the distance of the axis A of power transmission shaft 19 with tooth bar 15 on the pinion 17 is meshed.This means this regional inside crank transmission device 11 just the gear ratio between the main transmission for maximum, thereby can reach the highest rotating speed.When the distance of the tooth of pinion 17 and axis A increased, gear ratio just reduced, and if tooth bar 15 with having when axis A is meshed apart from the tooth of maximum, just that gear ratio reaches is minimum.This position can arrive after the dead point of leaving the back and folded back position at crank 13.

In first embodiment according to Fig. 1 and 2, the tooth 27 of tooth bar 15 is positioned within the annular recess 29 of connecting rod 13 ends.The zone that is positioned at tooth 27 opposites at connecting rod end has parallel with a tooth root basically slot-like opening 31, and wherein being equipped with one, be designed to can be at the slide block 33 that vertically moves, and is pressed on the slot-like opening 31 lower limit faces 37 by a pressing plate 35.Pressing plate 35 is preferably caught two thigh posts that be arranged in parallel, and each is positioned on the slot-like opening 31 with the side, and in the side it is covered in.Pressing plate 35 is hinged on the swinging axle 39 with an end, and is pressed on the slide block 33 with clockwise by a spring 41.The power of spring 41 is to limit like this, and promptly being meshed with the tooth of pinion 17 with the tooth 27 that enough can make tooth bar 15 at any time reliably is degree.

In the structure according to the second embodiment of the invention among Fig. 3, tooth bar 15 is that the guide edge 43 on the end 14 of the connecting rod 13 by being designed to fork shape is realized in the guiding on the pinion 17.As the reverse leading at edge 43 be constitute in the front side of pinion 17 one with its disk 45 with one heart, and work as spigot surface with its circumference 47.Disk 45 is preferably made the part of pinion 17, and is contained in the identical degree of eccentricity on the power transmission shaft 19 of shuttle travelling gear 22.Can guarantee like this to remain constant with the flank of tooth of tooth bar 15 engagements and the distance of the contact wire between the circumference 47 on the disk 45 that has spigot surface 43 on the end 14 of connecting rod 13.Connecting rod 13 borrows the side guiding of tooth bar 15 and spigot surface 43 to realize that it can prevent the lateral movement of end 14 on axis A direction of connecting rod 13 by the disk of not representing that is positioned on the power transmission shaft 19 in Fig. 3.This disk only slides on the bottom thigh post of the fork shape end 14 of connecting rod 13 because its position deviation contain a side of the crank end of tooth bar 15.

Connecting rod 13 and tooth bar 15 are preferably made as precision stamping spare, so as very critically with save into this locality and produce.

In pressing the embodiment of the invention of Fig. 5, on the position of tooth bar, replace by a rooted tooth shape belt 61, it is holding the pinion 17 that is provided with prejudicially on the one hand, is also holding a revolvable driven gear 63 that is driven swingably by connecting rod 13 on axle 75 on the other hand.A belt tension bar 65 that is loaded by spring 69 compensates the variation that is held length by the caused odontoid belt of the degree of eccentricity of pinion 17 with a regulating wheel 67.The variation that holds length is very little, because the degree of eccentricity of pinion 17 also is very little.

As a kind of replacement or additional, gear 63 also can be installed on the axle 77 prejudicially.If, also can adopt fan-shaped belt holder, because 61 of belts are carried out an extremely limited oscillating stroke anyway without pinion 17 and gear 63.

In Fig. 4, schematically illustrated sewing needle 9 with respect to shuttle 21 or shuttle tip 53 three possible thrust locational situation.On a of position, knowing at one sightIt can be seen at a glance in the position of sewing needle 9 and shuttle 21 is to thrust on " right side ".Position b represents that shuttle 21 and sewing needle 9 are to thrust in the centre, when being used for straight linear slit.And on the c of position, sewing needle 9 and shuttle 21 are to be in " left side " thorn implantation site.This figure shows: between pinprick 51 and shuttle tip 53 is to depend on the lateral position of sewing needle 9 and different size (different phase places) is arranged apart from B.Thereby just can make the shuttle tip can catch coil quickly by the rotating speed that improves shuttle 21 and shuttle tip 53 disposed thereon, thereby and can when the lateral position of the maximum possible of sewing needle 9, improve the reliability of needle tracking.

Claims (12)

1. the used transmission device of shuttle (21) of Sewing machines (1) comprises a pinion (17) and the toothed slave hand actuator that is guided back and forth by the crank gear (13) of swing on the power transmission shaft (19) that is arranged on shuttle (21), the same pinion of its tooth (27) (17) keeps engagement, and it is characterized in that: pinion (17) is on the power transmission shaft (19) that is arranged on shuttle (21) prejudicially.

2. according to the transmission device of claim 1, it is characterized in that: between crank gear (13) and pinion (17), be provided with a tooth bar (15) or an odontoid belt (61) as transmission mechanism.

3. according to the transmission device of claim 2, it is characterized in that: tooth bar (15) is provided with a spigot surface (43), and it is to be designed so that the same pinion of tooth bar (15) (17) keeps engagement.

4. according to the transmission device of claim 3, it is characterized in that: spigot surface (43) be design in a side setting tooth bar (15) below, on connecting rod (13) end unlimited or; In the closed slot-like opening (31).

5. according to the transmission device of claim 3 or 4, it is characterized in that: spigot surface (43) is to be arranged on coaxially on the positioning disk (45) on the power transmission shaft (19) with pinion (17) by being placed on one slidably.

6. according to the transmission device of claim 5, it is characterized in that: positioning disk (45) is the axially extended front end that is designed to as pinion (17), or is contained on the power transmission shaft (19) as independent parts.

7. according to the transmission device of claim 1 or 2, it is characterized in that: fix one by spring-loaded slide block (33) on the guide edge (37) of connecting rod (13), it can vertically move.

8. according to the transmission device of claim 7, it is characterized in that; The tooth that guide edge (37) is roughly parallel to tooth bar (15) extends, and is the part of connecting rod (13).

9. according to the transmission device of claim 7 or 8, it is characterized in that: slide block (33) can be pressed in downwards on the guide edge (37) by a spring-loaded lever (35).

10. according to the transmission device of claim 1, it is characterized in that: use an odontoid belt (61) as transmission mechanism, it is holding pinion (17) on the one hand, holding a belt holder or gear (63) on the other hand, this belt holder or gear (63) can carry out swingingly transmission by crank gear (13).

11. the transmission device according to claim 10 is characterized in that: odontoid belt (61) keeps tensioning with a spring-loaded nutted rod (65) and a regulating wheel (67) that is fixed on above it.

12. the transmission device according to claim 10 or 11 is characterized in that: driven wheel (63) is arranged on the axle (77) prejudicially.

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